Trinuclear polymethine dyes containing a pyrryl indolyl, or pyrrocolyl nucleus



Patented 1 1954 v 2,665,761 UNlTED ifl STATES PATENT. ion-Ice g 2,668,761 TRINUCLEAR POLYMETHINE' DYES CON- 7 y TAINING A PYRRYL INDOLYL, ORPYRRO- 'COLYL NUCLEUS 1 I ]'Donald W; Heseltine and Leslie G. S. Brooker, 7 Rochester, N. Y., assignors to Eastman Kodak 7 Company, Rochester, N. Y., a corporation of New Jersey 'No Drawing. Application January 23, 1952, t

. I Serial No. 267,928

9Clai 1'ns. (o1. zoo-240.1), 7

This invention relates to polymethinev dyes (phenylmethyl), e-phenylethyl, p-carboiryethyl, and more particularly to trinuclear polymethine carboxymethyl, ,a -carboxyethyl, -carboxypropyl, dyes containing a pyrryl, indolyl, or pyrrocolyl {i acetoxyethyl, 'y 7 acetoxypr'opyl, carbomethnucleus. The dyesof our invention can be more oxymethyl, l s-carbomethoxyethyl, carbethoxyaccurately described as polymethine dyes con 5 methyl, B-carbethoxyethyl, p-sulfoethyLQphehyltaining a pyrryl, indolyl, r pyrrocolyl nucleus mercaptomethyl,v phenoxymethyl p-phenylmer- V substituted on the polymethine bridge Or intercaptoethyl, p-phenoxyethyl, etc. (especially an cyclic chain. alkyl group containing from 1' to carbon'atoms) Polymethine dyes containing a pyrryl,-indolyl, R1 represents a hydrogen atom, an alkyl group, or pyrroc lyl n leu h e l g b e own. l- 10 such as methyl, ethyl, etc., or an aryl group, such though such dyes have'not, in general, been as phenyl, 0-, m-, and p-tolyl, o-, m-, and pfound to be especially useful in sensitizing photochlorophenyl, etc. (e. g. a mononuclear aromatic graphic silver halide emulsions. Such prior art group of the benzene series). R3 represents a dyes have been used to advantage in photohydrogen atom, an alkyl group, such as methyl,

graphic elementsas light-filtering agents, howethyl, n-propyl, n-amyl, n-heptyl, n-dodecyl, v cyclohexyl, etc. or an aryl group, such as phenyl, We have now found a new class of trinuclear 0-, m-, and p-tolyl, etc., and R2 and R3 together dyes containing a pyrryl, indolyl, or pyrrocolyl represent the non-metallic atoms necessary to nucleus which are especially usefulin sensitizing complete a heterocyclic nucleus of .the pyridine photographic silver halide emulsions. v series, Z and Zreach. represents the non-metallic It is, therefore, an object of our invention to atoms necessary'to complete a heterocyclic nuprovide a new class of trinuclear dyes containing cleus containing from 5 to 6 atoms in the heteroa pyrryl, indolyl, or pyrrocolyl nucleus. Another cyclic ring, such as'those selected from the group object is to provide methods of making such consisting of those of the thiazole series (el' g. dyes. Still another object is'to provide photo thiazole, 4'-methylthiazole, 5-methylthiazole, 4- graphic silver halide emulsions sensitized with phenylthiazole, 5 -phenylthiazole, 4-,5-dimethylour new dyes. Another object is to provide a thiazole, 4-(2-thienyDthiazole, etc.), "those of method of preparing such emulsions. A furthe benzothiazole series (e g. benzothlazole, 4- ther object is to provide a new class of interchlorobenzothiazole, 5-chlorobenzothiazole, 6- mediates which are useful in preparing our chlorobenzothiazole, 'I-chlorobenzothiazole, 4- new dyes. Other objects will. become apparent i methylbenzothiazole, 5 methylbenzothiazole, from a consideration of the following description 6 methylbenzothiazole, 5 bromobenzothiazole, and examples. I fi-bromobenzothiazole, 4-phenylbenzothiazole, 5- According to our invention we provide new phenylbenzothiazole, 4-methoxybenzothiazole, 5- trinuclear dyes containing a pyrryl, indolyl, or methoxybenzothiazole, 6-methoxybenzothiazole, pyrrocolyl nucleus selected from those repre- 5 iodobenzothiazole, 6 iodobenzothiazole, sented by the following generalformulas: 4 ethoxybenzothiazole, 5 ethoxybenzothiazole,

R--I T( OH=CH),,-1 U=CHC=CH(L-L)- 16(:==CH-e-CH) :NR1

q. tetrahydrobenzothlazole, 5,6 dimethoxybenzodroxybenzothiazol'e, v6 hydrokybenzothiazole,

y fi p etc.), those of the naphthothiazole series (e, g. R 0 gr 4 a-naphthothiazole, B-naphthothiazole, 5-'methi oxy-e-naphthothiazole', 5-ethoxy-fi naphthothiai zole, '7-methoxy-a-naphthothiazole, 8-methoxy-e- Ra naphthothiazole, etc.), thOSflIbf the thionaphwherein R and R1 each represents an alkyl group theno l'; 6', 4,5-thiazole'series (e. g. 4'-methoxy- (i. e. an alcohol radical), e. get y y thi0naphtheno'7',6,4,5-thiazole,etc.),those of the n-propyl, isobutyl, n-butyl, isoamyl, n-amyl, oxazole series (e. g. 4-methy1oxazole, S-methyle-hydroxyethyl, f-y-hydroxypropyl, s-methoxyoxazole, v 4-phenyloxazole, 4,5.-diphenyloxaaole, ethyl, fl-ethoxyethyl. allyl, p-methylallyl, benzyl 4 -ethyloxazole; 4,5-dimethyloxazq1e, 5-phe'n'y1- oxazole, etc.) those of the benzoxazole series (e. g. benzoxazole, -chlorobenzoxazole, 5-pheny1- benzoxazole, s-methylbenzoxazole, G-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 5-methoxybenzoxazole, "6-- 5-ethoxybenzoxazole, 6-'

drobenzoselenazole, etc.), those of the n'aphth'o' selenazole series (e. g. a-naphthoselenazole, B- naphthoselenazole, etc.), those of the thiazoline series ,(e. g. .thiazoline, 4-.methylthiazoline etc.),

those of the Z-quinoline series :(e. 'g; quinoline, 3-methylquinoline, 5-,methy'lquinoline, .7-methyl- 4 2-a1kylmercapto-4(5) -thiazolone series, such as 2'-;ethylmercapto-4(5)-thia2olone, etc., those 01 the thiazolidone series, such as l-thiazolidone or .its 3-alkyl (e. g. ethyl, etc.), 3-phenyl Or 3%- naphthyl derivatives, those of the 2-alkylphenyl- 'amino-4:('5)'thiazolone series (e. g. 2-ethy1- iphenylaminorlfi) -thiazolone, etc.), those of the .qu'inoline, 8-methylquinoline, fi-chloroquinoline,

B-chloroquinbline, S-methoxyq-uinoline, G-ethoxyquinoline, fi-hydroxyquinoline, .B-hydroxyquinoline, etc.),, those ofIthe 4-quinoline series (e. g. quinoline, fi-methoxyquinoline, 7-methylqu'inoline, 8-methylqulnoline, etc.), those of the l-isoquinoline series (e. g. isoquinoline, 3.,4-dihydroisoquinoline, etc.), those of the ,3-isoquinoline series '(e. g. isoquinoline, etc.), those of the 3,3- dialkylindolenine series (e. g. 3,3-dimethy1in- -.dolenine, 3,3,5-trimethylindolenine, 3,3,7-tri- .methylindo'lenin'e, etc.), those of the -2-pyr-idine series .(e.,g. pyridine, 3-methylpyridine, -methylpyridine, E-methylpyridine, 6-methylpyridine, 3,4-dimethylpyridine, 3,5-dimethylpyridine, 3,6- dimethylpyridine. 4,5-dimethylpyr'idine, 4,6-di- .methylpyridine, -chloropyridine, 5-chloropyridine, 6-chloropyridine, B-hydroxypyridine, 4-hydroxypyridine, 5-hydroxypyridine, S-hydroxypyridine, B-phenylpyridine, 4-phenylpyridine, G-phenylpyridine, etc.) those of the 4-pyridine .series (e. g. Z-methylpyridine, 3-methylpyridine,

2-chloropyridine, 3-chloropyridine, 2,3-dirnethylpyridine, 2,5-dimethylpyridine, 2,6-dimethylpyridine, Z-hydroxypyzidine, B-hydroxypyridine, etc.), etc. Z2 represents the non-metallic atoms necessary to complete a pyrrole nucleus (includes simple pyrrole nuclei and condensed nuclei, e. g. indole), X represents an acid radical, e. .g. chloride, bromide, iodide, thiocyanate, sulfamate, methylsulfate, ethylsulfate, perchlorate, benzenesulfonate, p-toluenesulfonate, xylenesulfo. nate, etc., L represents a methine group (substituted or unsubstituted, e. g. =CH-,=CCH3--, etc.), n and d each represents a positive integer of from 1 to 2, m and q each represents a positive 7 integer of from 1 to 3, and Q represents the nonmetallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, such as those selected from the group consisting of those of the thiazolone series, for example: those of the 2,4(3,5) -thiazoledione series, such as 2,4(3,5) -thiazoledione, 3-alkyl2,4(3,5) -thiazole'diones (e. g. 3-ethyl-2',4-

' (3,5-thia,zoledione, etc.), 3-pheny1-2,4(3,5)-thiazoledione, 3a-naphthyl-2,4(3,5)-thiazoledione,

' etc., those of the 2-thio-2,4(3.5)-thiazoledione (rhodanine) series, such as 3 -alkyl-2-thio-2,4-

(3,5)-thiazolediones (3-a1ky1rhodanines) (e. g. v-3-ethyl-2thio-2,4=(3,5)-thiazoledione or 3-ethyl- .rhodanine) 3-phenyl-2thio2,4(3,5) -thiazoledione (3-phenylrhodanine), 3-enaphthyl-'2-thio- 2,4( 3,5) thiazole'dione (3-a-naphthylrhodanine) 3-(1-benzothiazyl),-2-thio-2,4(3,5) -thiazoledione (,2-(l-benzothiazyl) rhodanine) etc., those of the ;'2"diphenylamino-4(5) -thiazolone series; those of the oxazoloneseries, for example: those of the '2-th'i'o-2,4.(3,5i)--oxazoledione series, such as 3- a1kyl.-2-thio-"2,4.(3,5)oxazolediones (e. g. 3- ethyl-2-thio-"2,4.(3,5) -oxazoledione, etc.), those of the 2-imino-2,4(3,5)-oxazolone (pseudohydantoin) series, etc.; those of the imidazolone series,

zoledione '(2-thiohydantoin) or its 3-alkyl (e. g.

3-ethyl, etc.), 3-phenyl 0r 3-anaphthyl derivatives as well. as its -1,3-dialkyl (e. g. 1,3-diethyl, etc.), .l-alkyl-3-Iphenyl (e. g. 1-ethyl-3-phenyl, etc.), l-alkyl-3-naphthyl (e. g. l-ethyl-s-anaphthyl) 1,3-diphenyl, etc. derivatives, those of the 2-alkylmercapto-5(4)-imidazolone series, such as 2-n-propylmeroapto 5(4) iinidazolone; those of the thionaphthenone series, such as 2(1) thionaphthenone or 1(2) -thionaphthenone; those of the pyrazolone series, such as pyrazolone or its l-alkyl (e. g, methyl, ethyl, etc.), l-phenyl, l-naphthyl (e. g. l-u-naphthyl), 3-alkyl (e. g. methyl, ethyl, etc. 3-phenyl, 3-naphthyl (3wnaphthyl), 1-alkyl-3-phenyl (e. g. 1-methyl-3 phenyl, etc.) 3-a-lkyl-1phenyl (e. g. B-methyl- 1-phenyl, etc.), 1,3-dialkyl (e. g. 1,3-dimethyl, etc.), 1,3-diphenyl, etc. derivatives; those of the oxindole series, such as 2,3-dihydro-3-ketoindo1e,

and like five-membered heteroeyclic nuclei;

those of the 2,4,6-triketohexahydropyrimidine series, for example, 2,4,6-triketohexahydropyrimidine (barbituric acid), 2thio-2,4,6tril:etohexahydropyrimidine (2-thiobarbituric acid) as wellas their l-alkyl (e. g. l-ethyl, etc.) or 1,3- dialkyl (1,3-diethyl. etc.) derivatives; those of the 3,4-dihydro-2('1)-quinolone series, such as 3,4 d-ihydro 2(1) quinolone (dihyd-rocarbostyril); those of the -3,4dihyclro-2(1)-quinoxalone series, such as 3,4-dihydro-2C1) -quinoxalone ('oxydihydroquinoxaline)i etc.; those of the 3- phenomorpholone (1,4,3-benzoxazine-3 (4) -one or benzo-,6-morpholone) series, such as {i -phenomorpholone, eta; those of the 1,4,2-benzothiamine-3(4) -one (ketodihydrobenzoparathiazine) series, such as ketodihydrobenzoparathiazine, etc., and like six-membered heterocyclic nuclei.

The new dyes of our invention represented by Formula I above can advantageously be prepared by condensing an intermediate selected from those represented by the following general forwherein R, R Rs, 2, Z2, 2: and n each have the values givenabove with a vcyclammonium quaternary salt selected from those represented by the wherein R represents an acyl group, such as acetyl, propionyl, benzoyl, etc. or a hydrogen atom, R6 represents an aryl group, such as phenyl, 0-, mand p-tolyl, etc., and e represents a positive integer of from 1 to 2; a halogen atom; etc.

The new dyes of our invention represented by Formula II above can advantageously be prepared by condensing an intermediate selected from those represented by Formula III above with an intermediate selected from those represented by the following general formula:

o=--b=or1(on=om 1-1 r-R1 wherein R7 represents an acyl group, such as acetyl, propionyl, benzoyl, etc.,-Rs represents an aryl group, such as phenyl, o-, m-, and p-tolyl. etc., and Q and q have the values given above.

The condensations of the compounds represented by Formula III with either. the compounds of Formula IV or the compounds of Formula V can advantageously be accelerated by heating, e. g. at temperatures varying from room temperature (about 20 C.) to 100 C., or to the reflux temperature of the reaction medium. Inert solvents, such as the aliphatic alcohols, e. g. ethanol, n-propanol, n-butanol, etc., 1,4-dioxane, pyridine, etc. can be used. Basic condensing agents can also be employed to advantage. Typical basic condensing agents comprise the trialkylamines (e. g. triethylamine, tri-n-propylamine, tri-n-butylamine, triisoamylamine, etc.), the N,N-dialkylanilines (e. g. N,N-dimethylaniline, N,N-diethylaniline, etc.), the N-alkylpiperidines (e. g. N-methylpiperidine, N-ethylpiperidine, etc.), etc.

The intermediates represented by Formula III can advantageously be prepared by condensing a cyclammonium quaternary salt selected from those represented by the following general formula:

wherein R represents an alkyl group, such as methyl, ethyl, etc., and a compound selected from those represented by the following general formula:

HC --';ZS

whereinRz, and R3, and Z2 each have the values given above. One instance of the preparation of an intermediate Formula III can be represented by the following equation:

wherein R, R2, R3, R, and X have the values given above. The intermediates represented by Formula III above are new. The intermediates of Formula IV wherein Y represents a fi-arylaminovinyl or a-arylaminobutadienyl group have been previously described in the art. (See, for example, British Patent 344,409, accepted March 4, 1931.) The intermediates of Formula IV wherein Y represents an electro-negative group are also well known. (See, for example, British Patent 424,559, accepted February 18, 1935.) The intermediates of Formula V have also been previously described in the art. (See, for example, Dains et al.-Jour. Am. Chem. Soc., vol. 31 (1909), p. 1148; vol. 35 (1913), p. 959; vol. 38 (1916), p. 1841; vol. 40 (1918), p. 562; vol. 44 (1922), p. 2310; Berichte, vol. 35 (1902), p. 2496; and U. S. Patent 2,548,571, issued April 10, 1951.) The intermediates of Formulas VI, VII, and VIII have also been previously described in the art. (For example, those of Formula VI in U. S. Patent 2,537,880, issued January 9, 1951, those of Formula VIII in British Patent 529,440, accepted November 21, 1940, and those of Formula VII in U. S. Patent 1,994,563, issued March 19, 1935.)

The following examples will serve to illustrate more fully the'manner whereby we practice our invention.

Example 1 .-9- (1 -ethyl-2,5-dimethyl-3-pyrryl) 3,3-dimethylthiacarbocyanine iodide C 1110 \IT CH: 3 0235 .additionofwater (@100 ml. Ihe crude dye was filtered off, dried and then recrystallizedirom methyl alcohol; after two recrystallizations .the

yield of pure dye was 0.78 gram (58 percent);

melting point 169-170 C.

Example 2.9- (1 -ethyl-3,5-dz'methyl-3-pyrryl) 1',3-dimethylthia-2'-carbocyanine iodide Example 3..-.1Methyl-941-ethyl-2,5-dimethyl- 3-py77fyl.) -3-.methylthia.-4'-carbocyanine iodide 1-ethyl-2,3',5,6 tetramet-hyl 3 pyrrolothiacarbocyanine iodide (1.09 grams, 1 mol.) 1- ethyl-4-ethylmercaptoquinolinium bromide (0.75 gram, 1 mol.) and triethylamine (0.7 ml., 2 mol.) were heated under reflux in ethyl alcohol ml.) f r 15 minutes.

Example 4.--3,3'-.diethyl-9- (1 ethyl 2,5 dimethyZ-.-3-pyrryl) -thiadicarbocyanine perchlorate 1,3'- diethyl 2,5,G-trimethyl-S-pyrrolothiacarbocyanine iodide (1.13 grams, 1 mol.), Z-B-acetanilidovinylbenzothiazole ethiodide (1.13 grams, 1 mol.) and triethylamine (0.7 ml., 2 mol.) were refluxed in ethyl alcohol (15 ml.) for 15 minutes. h crude. dye was. precipitated y the addition of aqueous sodium perchlorate (2 grams in 50 1111.). The. crude dye was filtered ofi, dried and twice recrystallized from methyl alcohol. The yield of pure dye'was 0.97 gram (65 Percent); melti point. 205F130? a I Example .saaa-ethylast [-14.-(3-.ethyl2 (3H) -benz0- thiazolylidene) -3- (1 -;ethyl'-, 2,5 --..dim,ethyZ-- 3-- pyrryl) butenylidenelrhodanine 1,3 diethyl 2,5,6 -"tr'imethyl 3 pyrroloithiacarbocyanine iodide (0.75 gram, 1-mol.), 'acetanilidomethylene 3 ethylrhodanine 0.55 -gram,'-1mol.-) "and'triethylamine (0.5 ml., 2 mol.) were refluxed in ethyl alcohol (15 ml) for 30 minutes. The crude :dye was thrown out of solution by the addition of water (100 ml.) filtered, dried and twice recrystallized from pyridine and methyl alcohol. The yield of pure dye was 0.58 gram percent); melting point 192-l93 (3.

Example '6.-3,3' climethyl 9 (2 phenyl 1 pyrrocolyl) 4,'5,4',5' dibenzo'lhiacarb'ocyam'ne p-toluene-suljonate 3 methyl 2 phenyl 4',5 benzo 1 pyrrocolothiacarbocyanine p toluenesulfonate (1.51 grams, 1 mol.), l-methyl-Z-methylmercaptonaphtho [1,2] thiazolium p-toluenesulfo- 'nate (1.05 grams, 1 mol.) and triethylamine (1.4 ml., 1 mol.+300% excess) were refluxed in ethyl alcohol (20 ml.) for twenty minutes. The reaction mixture was chilled, filtered, and the crude dye was washed with ether, water, and acetone, and dried. After two recrystallizations from methyl alcohol, the yield of purified dye was 25%; M. P. 294-5" C. dec.

Example 7.--3 ethyl 9 (1 ethyl 2,5 d2- methyl 3 pyrryl.) 3 methyl 4,5,4,5' dibeneothiacarbocyanine iodide 1 ethyl 2,3',5,6 tetramethyl 4,5' benzo S-pyrrolothiacarbocyanine iodide (1.22 grams, 1 mol.) 1 ethyl 2 ethylmercaptonaphtho [1,2] thiazolium bromide (0.90 gram, 1 mol.) and triethylamine (0.5 gram, 1 mol.+100% excess) were refluxed in ethyl alcohol (15 ml.) for thirty minutes. After chilling the reaction mixture, the

crude dye was filtered off, washed with ether, water, and acetone, and then dried. After two recrystallizations from methyl alcohol, the yield QI purifie We wa 20%;. M. P. 22 de cyanine p .Example 8. 9 (2.5,- dimethyl 1 phenyl s pyrryl) 3,3 dimethyl 4,5,435 dibenz i r acarbocyanineiodide Example 9.3,3-diethyl-9-(3-indolyl) -4,5,4',5'-

dibenz selenathiacarbocyanine iodide 3' ethyl 8 methyl 4',5' benzo 3 indolothiacarbocyanine iodide (0.50 gram, 1.

SOj-CgHr-CHKP) 2,3,8-trimethyl-4',5-benzo-3-indolothiacarbo- -toluenesulfonate (1.04 grams, 1 'mol.),.; l methyl 2' methylmercaptonaphtho [1.2]- thiazolium p-tolue'nesulfonate (1.26- grams, 1 mol.+50% excess) and triethylamine (0.8 gram, 1 mol.+300% excess) were'dissolved in'ethyl al- Example 11.- (1,3 dimethyl- 2 i11.clolyl) 3,3 diethyl 4,5,4',5' dibenzothiacarbocyam'ne bromide l 3 ethyl 1,3,8 trimethyl 4',5' benzo 2 indolothiacarbocyanine bromide (0.57 gram, 1 mol.) 1 ethyl 2 ethylmercaptonaphtho[1,2]- thiazolium bromide (0.71 gram, 1 ml.+100% excess) and triethylamine (0.6 ml., 1 mol.+300% excess) were refluxed in ethyl alcohol ml.) for thirty minutes. The reaction mixture was filtered hot and the crude dye thoroughly washed with methyl alcohol and dried. After two recrystallizations from methyl alcohol, the yield of purified dye was 32%; M. P. 2423 C. dec.

Example 12. s,3' d'imethyl 9 (2 methyl 3 indolybozcacarbocyanine perchlorate 2,3,8 trimethyl 3 indoloxacarbocyanine iodide (2.15 grams, 1mol.),I-3 methyl 2"-'. methylmercaptobenzoxazolium 'p t'oluenesulfonate (3.4 grams, 1 m0l.+100%v excess) and triethylamine (1.4 ml., 1 m0l.+100% excess) were refluxed in ethyl alcohol (20 ml.) for twenty minutes. The reaction mixture was chilled and the dye converted to the perchlorate by the addition of sodium perchlorate (5 grams) in Water (100 ml). The crude dye,- after thoroughly washing with water and ether was dissolved in methyl alcohol-(10 ml.),- again precipitated by the addition of aqueous sodium perchlorate and then stirred until crystalline. The product was then filtered off and twice recrystallized from methyl alcohol. The yield of purified-dye was 14%; M. P. 199-200 C. dec. I 1

Example 13.- 3,3 dimethyl 9 (3 pyrryl) 4,5,4',5' d ibenzothiacarbocyanine p-toluenesulgfonate i 3 osolactmecflxp) 3',6 dimethyl 4'5 benzo -13 pyrrolothiacohol (15 ml.) and heated under reflux for one carbocyanirie p-toluene sulfonate (0.95gram, 1

ncur. I The reaction mixture wa'sllchille'd and filtered and the crude dye was'washed with water "and acetone and dried." After two recrystallizations from methyl alcohol; the yield of l purified 4 .ia1cohol;;(15 ml.) ;ior thirty..minutes.

dye was 42%; M. P. 287-8 C. dec.

mol.), 1 methyl 2 methylmercaptonaphtho- [1;2lthiazolium .p-tolu'enesulfona'te' ("1.66 grams, -'-1 m0l.+100% excess) and thiethylamine .'(1.l =-ml., 1 mo1+300% excess) were refiuxedimethyl .Thereac- 11 tion mixture was chilled and'filtered and the crude dye washed with methyl alcohol and dried. After two recrystallizations from methyl alcohol the yield of purified dye was 47%; M. P. 272-3 C. dec.

The following examples will serve to illustrate more fully. the'mannerwhereby we prepare the new, intermediates represented by Formula III above.

Example 14.--1,3' 7 dieth yl 2,5,6 trimethyl 3 pyrrolothzacaz hocganine perchlorate 2H: 3-ethyl-2 methylbenzothiazoliump toluenesulfonate (34.9 grams, 1 mol.), 1-ethyl-2,5-dirnthylpyrrole (14.6 grams, 1 mol.+ percent excess) and ethyl orthoacetate (24.3 grams, 1 mol.+200 percent excess) were refluxedin ethyl alcohol (25 ml.) for 4 hours. The reaction mixture. was chilled and treated with aqueous sodium iodide (20 grams in 150 ml.). The solid which separated was filtered off and discarded. The filtrate was treated with an additional 400 ml. of water and chilled overnight. The prod- .uct which separated was filtered off, washed with acetone and dried. After conversion to the perchlorate and two recrystallizations from methyl alcohol (and filtered through decolorizing car- 'cin. c104 bon) the yield of pure dye was 4.5 percent;

melting point 188 -190 CI AnaZysis.Calculated for C20H25C1N2O4S2 C, 56.54; H, 5.93. Found: C, 56.9; H, 6.7.

Example 15.-1 ethyZ-2',3',5,6 tetramethyl 3- pyrrolothz'acarbocyanine perchlorate Replace the 3-ethyl-2-methylbenzothiazolium Example .16. .1"-tm1z-2,2 ',aa-t r methyz-r.5- benzo-Smyrrclothiacarboziyanine iodide LZ-dimethyl'naphtholl,2]thiazoliump tolul'uenesulfonate. (38.5. grams, 1 mol.), 1 ethyl-2,5 .dimethylpyrrole grams. 1 mol.+l0% excess) ethyl orthoacetate (24.3. grams. 1

mole-200% excess) were" refluxed in ethyl alco- 1101 ml.) for three hours. The reaction mixture was then treated with sodium iodide (20 grams) in water (200 ml.), chilled overnight and the solid filtered off and discarded. The solution was treated with an additional 200 ml. of water, chilled, and the aqueous layer decanted. The oily layer was repeatedly washed with water and ether and finally treated with aqueous sodium iodide. The aqueous layer was decanted and the residue'stirred with acetone until crystalline and then filtered and dried. The crystalline product was stirred with cold pyridine (30 ml.), filtered, and the residue discarded. The pyridine solution was treated with stirring with ether '(100'ml.) and the solid product filtered oil and washed with ether. After two recrystallizations from methyl alcohol, the yield of pure dye was 14%; M. P. l73-4 C. dec.

Example 17.--2,3';5.6-tetramethyl 1 phenyl- 4.5-benzo-3-pyrrolothiacarboci/anine iodide 1,2-dimethyln'aphtho[1,2lthiazolium p toluenesulfonate (38.5 grams, 1 mol.), 2,5-dimethyll-phenylpyrrole (20 grams, 1 mol.-|-10% excess) and ethyl'orthoacetate (25.0-grams,1 mo1.+200% excess) were refluxed in. ethyl alcohol for three hours and then treated with sodium iodide (20 rams) in water (400 ml.) and chilled overnight. Thefaqueous solution was decanted and .the residue washed with water and ether and finally stirred with acetone until crystalline. The crude dyewas filtered off and then boiled with water (290 ml.) and filtered hot. The residue was washed with acetone and dried. After two recrystallizations from methyl alcohol (and filtered through decolorizing carbon) the yield of pure, dye was 2%; M. P. 192-3 C. dec.

Example 18'.--3'-ethyl-8-methyZ-4,5-benzo-3- indolothiacarbocyanine iodide l-ethyl-z-methylnaphtho [1,2lthiazo1ium p-toluenesulfonate '(20 grams, 1 mol.), indole (7.5 grams, 1 mold-20% excess) and ethyl orthoacetate ('16 grams, 1 mol.+300% excess) were dissolved inacetic acid(25.ml.) and heated under reflux for.30 minutes. The reaction mixture was cooled, poured. into water (200 ml.) and stirred with ether '(200 ml.). The ether-and water were decanted and the crude dye was washed with water, dissolved in ethyl alcohol and converted to the iodide by the addition of sodium iodide (5, grams) in water-(50 ml.). The crude iodide wasfiltered off, washed with acetone and dried. .Aftertwo recrystallizations from methyl alcohol, theyield ofupure-dye was, 5%; M. P. 231--3" C.

dec.

1a Example 19.2;3',8-trimethyl-4,5'-be1tzo 3-i1tdolothiacarbocyanine p-toluenesulfonate Example 20.3' -ethyZ-1,3',8-trimethyl-4,5'-benzo-2-indolothiacarbocyanine iodide '1-ethyl-2- methylnaphtho[1,2lthiazolium ptoluenesulfonate (20 grams, 1 mol.), 1,3-dimethylindole (7.25 grams, 1 mol.) and ethyl orthoacetate (16.2 grams, 1 mo1.+300% excess) were dissolved in acetic acid (25 ml.) and heated rapidly to boiling over a. free flame and boiled for thirty seconds. The reaction mixture was then poured into water (200 ml.)" and treated with sodium iodide (20 grams). The aqueous portion was decanted and the solid washed with water. The dye was extracted from the quaternary salt with five 200- ml. portions of acetone. The acetone solutions were concentrated to 25 ml., chilled, filtered, and the crude dye dried. After two recrystallizations from methyl alcohol the yield of pure M. P. 209-10 C. dec.

Ercample 21.2,3',8-trimethz/l- '-indoloxacarbocyanine iodide 2,3-dimethylbenzoxazolium iodide (11.0 grams, 1 mol.), 2-methylindole (5.3 grams, 1 mol.), and

14 and acetone; After two recrystallizations. from methylv alcohol the yield was 9%; M. P. 263"4? C.

dec., I I Ei-ample 22.-3,6-dimethyl-4',5'-benzo-3-pyrrolothz'acarbocyanine p-toluenesulfonaie osoi-omondp) 1,2-dimethylnaphthoE1,2]thiazolium p-tolu- 'enesulfonate (14.3 grams. 1 mol.), pyrrole (8 grams,v 1 mold-20% excess) and ethyl orthoacetate (16.2 grams, 1 mo1.+300% excess) were refluxed in ethyl alcohol (50 ml.) for two hours. The reaction mixture was poured into cold water (2 00 ml.) and stirred until crystallization started. The mixture was then chilled, filtered, and the crude dye washed with water, ether, and acetone. After two recrystallizations from methyl alcohol, the yield was 8%; M. P. 223-4 C. dec.

Example 23.3'-methyZ-Z-phenyl-4,Sf-benzo-I- pyrrocoloth iacarbocyaninep-toluenesuljonate Replace the 2-methylindole of Example 19 with a molecularly equivalent amount of 2-phenylpyrrocoline. The dye was obtained as a thick oil, and was used as such in preparing the dye of Example 6.

We have found that our new dyes spectrally sensitized photographic silver halide emulsions when incorporated therein. The dyes are especially useful for extending the spectral sensitivity of the customarily employed gelatino-silverchloride, gelatino-silver-chlorobromide, gelatinosilver-bromide and gelatino-silver-bromiodide dye'was 3%";

ethyl'orthoacetate (10 grams, 1 mol.+200 excess) 0 were refluxed in acetic acid (15 ml.) for twenty minutes. The reaction mixture was then poured into cold water (200 ml.) and was treated, with ether m1). The-mixture was then filtered a h cru ed e waswasn d withwatesetner. is hr iienout the emulsions.

developing-out emulsions. In the foregoing examples, the extent to which gelatino-silverbromiodide developing-out emulsions can be sensitized as well as the point of maximum sensitivity are pointed out in connection with the dye of each example. To prepare emulsions sensitized with one or more of our new dyes, it is only necessary to disperse the dye or dyes in the emulsions. The methods of incorporating dyes in emulsions are simple and are known to those skilled in the art. In practice, it is convenient to add the dyes to the emulsions in the form of a solution in an appropriate solvent. Methanol has proved satisfactory as a solvent for most of our new dyes. Where the dyes are quite insoluble-in methyl alcohol, for instance, a mixture of methanoland pyridine is-advantageously employed as a solvent. The dyes are advantageously incorporated 'in the finished, washed emulsions and should be uniformly distributed amm- Thewoncentrationmt the dyes-sin-theaemulsionsa canwvarywwidely, e; g: from-filte 100mg:- pen-liter of fiowable emulsion. The concentration of'th'e dyes will vary accordingly to the type of emulsion and according to the efiecta desired: suitable v and: most '1 economical concentration for any given emulsion will be apparent to those skilled in the art, upon makingwthehordinary tests and observations customarily used in the art of emulsion: making. T prepare aagelatino-silverhalide emulsion sensitized with .lone or more of our new dyes, the following procedure is satisfactory:

A quantity of dye is dissolved in methyl alcohol (or a mixture of methylalcohol and pyridine) and a volume of thissolution, ,whichwmaybedilutedrwith water, containing from 5L t'o 1 00II'ng. of dye, is slowly addedt'o about 1000 cc; ofg'elatino-silver-halidevemulsion, with. stirring; Stir?- ring is continuedjuntil thedye is thoroughly, dispersedin' the emulsion.

With most .ofour'dyes, from to 201' mg, of dye per liter of' gelatino-silver-bromide or bromiodide emulsion (containing about? 40" g, of

silver halide) suflioes to produce thetmaximu'm' sensitizing effect. With the finergrain emulsions, somewhat larger concentrationof dye-may, be needed to produce the maximum sensitizingef fect.

The "above"statements 'are only illustrative;

it will *be' apparent" that "the dyes'"carrbe incorporated in photographic emulsions by any of the other methods customarily employed xin the art, e. g. by bathing a plateor film upon which an emulsion is c'oated-jin'a solution of ithe dye in an.

appropriatesolvent. However;.bathingmethods are ordinarily notto be preferred; Emulsions sensitized with the dyes can be -coated on suitable supports, such :as glass, celluioseederivative film, resin film or paper in the usual manner.

When preparing intermediatesrasidescribed in Example 22 above, wherein unsubstituted pyrrole is; employed the: condensation nught-resultiin the formation of; 3,-,6.-,--.dimethyl-\--:4,5f horizon-- 2? pyrrolothiacarbocyaninap;-toluenesulfon'ate; alathoughmresent-evidence favors the compound (16"? picted in Example 22.

What we claim; as: our: invention a and desire i811, 1-7 A polymethine; dye selected from-those replie entedon: the "follcwineigenerai .formula;

The

secured: iby Lettersviatentwcofs theX-:United=. States-' 1B 7 2,.u'lfheepol-ymethinen dye having the following formula;

3;;The'i'polymethine dye" having the following formulaoso'z-ctnecmtpi- 4. The polymethine dye having the following formula:

HC C I OH: 6 6

SOHCaHE-CHAD) 5. The polymethine dye having the" following formula:

6= A -process for preparing polymethine dyes comprising? condensing a compound selected wherein Rzfand Rieach represents anialiiyrsgroup;

R2 and. R3 each represents -awmember: selected from theqgroup consisting o awhydrogen atom; an alkyl group;- and an' -arylagrouprand-Ri -and Rt: togetherrepresent-the non-metallic ratoins' necessary" to completea heterocyclic nucleus of the pyridine-series; z and' ziieac represents' the non metallic atoms necessary' to complete a heterocyclic nucleus' containing from s to catoms in' the heterocyclic ring; 2 Zir Tepr8S8IltSFth'IlOH metallic 1atoms-necessaryto ,complete -a vhetero= cyclic-nucleus-=of-'the pyrrole seriesi'X'represents an acid radical; =L represents amethrne group; and d ='each'" rep resents* ax-positi've integer of fromlto 2.

from those represented by thefdllowing general formulae CIH; nq it w 11--cH ;;i1 -0o H='( J 'c- ;z; x Br e I wherein 'Rire'p'resents an alkyl'. group, R2 and R3 each" representsaa member selected from the group", consisting of a "hydrogen atom, an alkyl roup;andanaryl'group, and-R2 and R3 together -represent-"the non metallic"atoms necessary 4 to :oiripi 'ate a heterocycli'c'. nucleus ofi'the-"pyridine series =zae resemsahe non metame-atoms'-nec- 17 essary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the pyrrole series, X represents an acid radical, and n represents a positive integer of from 1 to 2, with a compound selected from those represented by the following general formula:

wherein R1 represents an alkyl group, Z1 represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, X1 represents v7. A process according to claim 6 wherein the condensation is carried out in the presence of a basic-condensing agent.

8. A process according to claim 7 wherein triethylamine is employed as the basic condensing agent.

9. The polymethine dye having the following formula:

DONALD W. HESELTINE. LESLIE G. s. BROOKER.

No references cited. 

1. A POLYMETHINE DYE SELECTED FROM THOSE REPRESENTED BY THE FOLLOWING GENERAL FORMULA: 